Deep well bridge



Feb. 11, 1958 w. R. MURROW ETAL DEEP WELL BRIDGE Filed Oct. 26-, 195511v moms DEEP WELL BRIDGE William R. Murrow, Independence, Kans., andAlpheus L. Connally, Efiingham, lll., assignors to The M & MManufacturing Company, Independence, Kans., a corporation of KansasApplication October 26, 1955, Serial No. 542,856 7 Claims. (Cl. 166-192)The invention relates to deep wells common in oil fields and moreparticularly to a device for effecting a bridge in the well at anydesired point in its height to serve as a plug or to facilitate pumpingfrom a part of the well spaced above the bottom of the well.

One of the objects of the invention is to provide a light weight,inexpensive bridge which may be lowered into the well without likelihoodof the bridge being caught as it is being lowered.

Another object is to provide a bridge which may be readily destroyed bya drilling tool after its usefulness has been terminated and it isdesired to pump the well from a lower level.

Another object is to utilize a bridging device which will freely drainfluid from above the device when it is first installed and before thebridge is completed by the dumping of concrete, sand, or the like on thebridge device.

These general objects and other detail objects as will appear from thefollowing description are attained 'by the structure illustrated in theaccompanying drawings, in which:

Figure l is a section through spaced portions of a deep wellillustrating some of the conditions encountered in the use of the bridgedevice and showing the device in dilferent positions ash is being pushedor thrust down the casing and through a window, which is an open sec-:tion in the casing, by the weight of the drill stem, or the like, tothe desired position.

Figure 2 is in part a side elevation and in part a longitudinal sectionthrough the bridge device showing it applied to the lower end of a drillstem or the like.

Figure 3 is a transverse horizontal section on the line 33 of Figure 2.

The bridge device comprises an elongated tubular central frame orbody 1. A series of fingers 3 of spring material have their lower endssecured to frame 1 and extend upwardly and outwardly therefrom and haveupwardly pointed terminals 5 adapted to dig into rock or shale formationof a well, or the casing of a well, or the threads or collars of thecasing to resist upward movement of the device from its desired positionin the well.

A series of ribs 7 of spring material are secured at their lower ends tothe central frame 1 at a point substantially higher than fingers 3 andextend outwardly and upwardly above the level of fingers 3 and form asupport- :ing cage for a web member 9 of canvas or similar flexiblematerial, the upper edge of which is folded over as indicated at 11 andgripped between return bend portions .13 of ribs 7, which hold the upperedge of the web taut when the ribs spread out and protect the upper edgeof the web from being chafed or torn by frictional contact with thesides of the well as the device is thrust down "the casing, etc.

An adapter or mounting piece 15 has a threaded tapered upper portion 17for engagement with the lower end of a 'rigid suspension member, such asa drill stem, or jars, or the like.

The piece 15 has a downwardly facing shoulder 21 for tes Patent 0seating the upper end of frame 1. A reduced diameter portion 23 of piece15 extends downwardly into frame 1, thereby providing perfect alignmentof the bridge, or device, with the drill stem and the well. A series ofwire springs 25 are secured to the inner upper portion of frame 1 andproject downwardly and towards the axis of the frame and have theirlower ends 27 bent outwardly to engage the inner wall of the frame.Springs 25 yieldingly engage the lower portion 23 of piece 15 andfrictionally retain the bridge and portion 23 assembled during theinsertion of the bridge into the well, but readily release the bridgefrom the mounting piece 15 when the drill stem 19 is raised and points 5engage the rock or shale formation of the well or a ridge or otherirregularity in the casing of the well.

The yielding fingers 3 and ribs 7 adapt the bridge for insertion indifferent sizes of casings and the fingers and ribs may spread outwardlybeyond the diameter of the casing to engage the shale or rock formationsurrounding the casingwhich is is being used in a well in which a windowsection of the casing has been eaten away by acid or removed bymechanical means. thereby permitting the forming of a bridge in thecasing, above or below this window, or in the rock formation of thewell, upon which an explosive charge may be placed and exploded, or thesection from which the casing has been removed may be treated by otheroil or gas field practices, such as perforating, fracturing oracidizing, or any combination of the above.

The vertical spacing of fingers 3 and ribs 7 (which elements serve asupper and lower guides for the bridge structure and the lower end of therigid suspension member), together with the centering of the upper endof the device on mounting piece 15 insures the lateral stability of thedevice as it is lowered into the well so that, when the device isreleased by the removal of the drill stem, it will be positioned asshown in Figure 1 to provide a baffle which will engage concrete, rock,etc. applied to web 9. The alignment-maintaining feature prevents thebridging device being inclined to the well axis so as to be deflectedout and into the open window section irrespective of the vertical andtransverse extent. of the latter.

A downwardly pointed conical guide member 29 is secured to the lower endof frame 1 and facilitates the movement of the frame through fluid orloose material in the well under the thrust of the drill stem. The lowerportion of frame 1 and of member 29 is apertured at 31 to drain fluidwhich may gather within the body prior to the completion of the bridgestructure and thus avoid the building up of a column of fluid ofsufiicient weight to push the bridge down further than desired beforethe concrete, sand, etc. has been introduced into the well.

With the device described above, any drilling crew can set a bridgewithout requiring outside help and special equipment other than theusual drill stem. When use of the bridge is finished, the light sheetmetal and fabric device may be drilled out readily for furtheroperations at a lower level in contrast to the resistance afforded byheavy cast iron structures in general use for similar purposes.

The details of the device may be varied without departing from thespirit of the invention and the exclusive use of those modificationscoming within the scope of the claims is contemplated.

What is claimed is:

1. A deep well bridge structure adapted to be releasably attached to thelower end of an elongate rigid suspension member for lowering into awell borehole, said structure comprising a body, a circular series ofspring-like fingers having their lower ends fixed to the exterior of thelower Patented Feb. 11, 1958 particularly desirable if the device 3, rportion of saidbody andproecting upwardly and outwardly-therefrom, aci-rcular series'of cantilever spring ribs axially spaced above saidfingers, said ribs having their lower ends fixed to said body, and theupper ends thereof projecting outwardly from the body, said andfi'ngersbeing ofa-length whereby in an unstressed condition the "upperendsiherebt describe peripheries of the borehole after detachmentof'said structure "from said suspension member, andquiclc-detachablerneans'for maintaining-saidbody andsaidisnspension member ina rigidcoaxiat relationship before release said structure by said suspensionmember. 1

2. A deep'well bridgejstructure as setforth'in' claim 1 which-furtherincludes-aweb of'fiexible material secured to-said ribs forretainingliquidconcrete and the like.

3; A deep well bridge structure as set forth in claim 2 in which thefingers :havetheir outer upper ends pointed to engage the sidesoftheborehole-and hold the bridge against upward-movement in the well, andthe ribs form acage for supporting the web ofiflexible material.

4. A deep well bridge structure as set forthin claim 2 in which thebody-projects below thelower ends of said fingers and isprovidedwithadownwardly pointed cuplike terminal for guidingandcenteringthe bridge as it is lowered into 'a well.

5. A deep well bridge structure as set forth in claim 2 in which the endportions of'the ribs are bent inwardly and downwardly and clamped overthe edge of the web to sustain the same in spread-open position and toprotect said edge against frictional contact with the sides of theborehole.

6. A deep well bridge structure as set forth in claim 2 n in which thebody is-an elongated sheet metal tube and is provided with a downwardlypointed conical cup at its lower. endjsaid cup and-the lower portion ofsaid tubehaving small apertures to drain :fiuid therefrom.

7. A deep well bridge structure asset forth in claim 6 wherein the lowerend of said suspension member is of smaller. diameter thanthe innerperiphery'of. the upper portion of said tube and wherein said means formaintaining said body andsa'id susepnsion'member in a rigid coaxialrelationship comprises a plurality of elongated springs projectinginwardly of said tube and each fixed at one endto the upper-portion ofsaid tube whereby said springs-frictionally retain the lower end of saidsuspensionrnember in assembled-relationship with said tube.

References Cited in the file of this patent UNITED STATES PATENTS

